The overall objectives of this project were to devise equipment and develop techniques whereby the performance of exercise and other types of human voluntary movement may be analyzed in terms of their underlying biophysical and biochemical components, and ultimately to apply the findings to rehabilitation medicine. During the first two years of the three year grant period, a number of objectives were met. Among them were: (1) The construction of a new motorized bicycle ergometer for both positive (concentric) and negative (eccentric) work exercise. (2) The development of an electrical recording system to allow the monitoring of integrated EMG (IEMG) from the quadriceps muscles. Using the above equipment and techniques a linear relationship has been established between IEMG and force exerted (work done) by the subject at a number of pedalling speeds for both muscle shortening (positive work) and stretch (negative work). In addition, a comparison of IEMG with the subject's oxygen uptake has provided a means of assessing changes in the metabolic rate of active muscle fibers. Goals for the final year of the grant period were established to extent the above work to cover as wide a range of pedalling speeds as possible thereby allowing a more comprehensive assessment of the biophysical phenomena involved.